I am sorry that this happen to you. I have been in a similar situation and is painful. I Will tell you my advices:I think I do and that’s why I’m here. You seem pretty knowledgeable, can I ask if you was in my position how would you go about asking the question in a way that won’t cause distress if she is indeed suffering and not stringing me along?
I think your relationship has finished and is not going to come back. You are in the friend zone now and this is not going to change
Please dont ask anything to her. If you ask her about it, It Will be worst, maybe she is overwhelmed with the question and this damage the friendship. And also, Who cares about the answer? I mean, she can answer nice words, but her acts says very clearly that she only want a friendship with you. So, the overthinking about the question Will only hurt you. I know is very difficult, but you have to Accept that she is only a friend
I think the question must be for yourself. Can you be Happy only in a friendship with her? Will you suffer If she dates with other people? If you can only be a friend, go on, be a friend, but you have to move on about the relationship hope or you Will suffer a lot